REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1903 167 



In a contribution to the American Journal of Science on the 

 limestone belts of Westchester county, Prof. J. D. Dana^ in 

 1880 made mention of the presence of corundum in iron ores 

 from this locality. Though he did not arrive at a true under- 

 standing of the mineralogic composition of these deposits 

 owing to his error in mistaking for chlorite, what Profes- 

 sor Williams later proved to be hercynite, he drew attention to 

 the abrasive quality of the material. A short time afterward 

 an emery mill was established at Peekiskill by the New York 

 Emery Co., which for a time ran on the ore from the immediate 

 vicinity, but it gradually abandoned the Peekskill ore, till in 

 1887 it was run almost exclusively on emery from Asia Minor. 

 It was finally closed up and has not been reopened. 



At the present time two companies are engaged in mining 

 this ore, the Tanite Co. of Stroudsburg Pa., which controls most 

 of the product, and the Ashland Emery and Corundum Co., 

 formed^ in 1900 by a combination of several of the leading emery 

 mills in the country. The output of this region was estimated 

 at over 1000 tons for 1896.^ An estimate of the average annual 

 output made in 1898 was from 500 to 700 tons per annum.^ From 

 the rapid growth of industries making use of the finished 

 products and recent developments in methods of manufacture, 

 a large increase in the output is to be expected. 



Mill treatment 



The final cleaning and grading of the roughly cobbed material 

 received from the mines is carried on by several different 

 methods which vary with the character of the matrix. 



The Norton Emery Wheel Co. of Worcester Mass. treat the 

 rough material by the following process, a description of which 

 was furnished to the writer by Mr Charles L. Allen, manager of 

 the company. The lumps are first crushed in a large stone 



'Am. Jour. Sci. Ser. 3. 20:9, 199. 



^'Min. Ind. 1£01. 10:18. 



'Min. Ind. 1900. 9:16. 



*Am. Inst Min. Eng. Trans. 28:567. 



